Harper, a six year old girl, wins the game that she plays with her imaginary friend, Drill. She won by causing messing with the floorboards on her tree house. She told her mom to step on the X, and she went crashing down to the ground. It is a fun, innocent childhood game.
FBI Agent Claire Bennigan, a child specialist, and Agent Jessup Rollins are assigned to the case. It's Claire's first case since her husband Sean died a couple months ago in a plane crash. While talking to Harper, they learn that another boy, Jackson, has played the game with Drill, but he lost. By lost, Harper meant that the kid died when he made a homemade bomb. His mother, however, survived.
Jackson's mom remembered seeing a man across the street while Jackson was playing his game with Drill. She managed to get a sketch of him, and what do you know, it's John Doe. He was watching Harper's house, and wrote Minx's name on a sheet of paper before collapsing and waking up in the hospital, not remembering anything about it or his own name.
Drill's moved on to a new friend - Minx Lawrence. Her dad, Wes, works for the government, Department of Defense. Oh, he also cheated on his wife, Lena. Drill was nice enough to break that news to Minx. While Minx is learning the game, Wes is in Africa on work.
In the Sahara dessert, petrified lightning appeared less than four months ago with an Air Force plane trapped in it. According to Wes, it looks like something or someone grabbed the plane out of the sky. Wes learns that it was Sean's plane that supposedly went down in the Arctic Circle. He calls Sean's wife, Claire, to let her know.
Remember how Wes had an affair? Yeah, that was with Claire. Wes tells Claire that Sean is no longer considered dead. He's considered missing. That's when the sketch that Jackson's mom did comes into Claire's inbox - it's Sean. John Doe is Sean Bennigan.
As if things weren't twisty enough, Claire's son Henry, who is deaf, is now talking to Drill. That's right, he can hear again, but Drill wants to keep it a secret.